1. Field of the Invention
The invention is directed to a device for sealing or occluding an opening of the large intestine (colon) or rectum of a patient and, as appropriate, for continuously and/or intermittently draining or removing stool therefrom, preferably into an external, bag-like collection container, the invention comprising an inflatable balloon with an approximately annular structure formed from a flat, everted tube section, wherein the outer layer of the everted tube section has a radially enlarged region (intrarectal balloon portion) for insertion into the rectum and is provided with a region that is tapered relative thereto (transanal balloon portion) and that remains at least regionally outside the rectum during use.
2. Description of the Prior Art
Devices for continuously draining or intermittently removing stool from the large intestine (colon) or rectum of a patient into an external, bag-like collection container, particularly also by means of a rectally administered enema of irrigation fluid, have been known for some years.
Drainage or collection of stool in the case of immobile, uncooperative patients is preferably carried out with the aid of so-called fecal collectors. These are bag-like structures that are adhesively attached in the anal fold just above the anal opening. Although preanal adhesive attachment is usually sufficiently stable and leaktight for short periods of use, maceration of the exposed skin surfaces is often observed as result of the continuously moist and chemically aggressive medium in the adhesion area.
An alternative is the use of so-called intestinal tubes, which are inserted through the anal canal into the rectum. Due to the accompanying risk of intrarectal injury, as well as the permanent dilation and thus the potential for damage to the sphincter muscle, intestinal tubes are normally used for stool drainage only on a temporary basis.
Systems for largely atraumatic stool drainage that can be used over the long term (indwelling fecal drainage), of the kind recently introduced by Zassi Medical Evolutions Inc., Florida, USA, and ConvaTec, New Jersey, USA, are structurally similar in design to balloon catheters for the continuous drainage of urine. Urine is drained from the bladder via a balloon-equipped catheter element and flows through a connected drainage tube into a collection bag. The balloon element in this case is used primarily to anchor the catheter in the bladder. It does also perform a sealing function to some extent, preventing urine from flowing down through the urethra past the shaft of the catheter. Analogously, the known stool drainage systems include a balloon-equipped head portion that anchors the device, collects the stool and conducts it away, and, connected to this, a tube element that debouches into a collection container.
Modern stool drainage systems such as the aforesaid also serve, in addition to the drainage function per se, the purpose of actively managing the fecal excretion of the patient within the context of stool management (fecal/bowel management) by therapists.
The concept of stool management includes the option of relatively high-volume or large-volume colorectal irrigation via the anus. Large-volume enemas into the colon have been used for decades for active excretion management in patients with surgically created colostomies. The irrigation fluid injected into the colon mobilizes the contents of the bowel and stimulates intestinal peristalsis, thus causing the colon to largely empty in a manner that is, so to speak, initiated or triggered by the user.
Similarly, the contents of the bowel in immobile, uncooperative, bedridden patients can be mobilized and drained by large-volume transanal enema. Defecation is thereby monitored and managed by the therapist. A stool-free, virtually continent interval of one to two days can be achieved in this way.
Colorectal enemas (so-called colorectal irrigation) have been used in clinical practice heretofore primarily to mobilize the stool in the presence of constipation or bowel voiding dysfunction.
For about ten years, the principle of colorectal irrigation has also been used very successfully in mobile, independent, incontinent patients who for a wide variety of reasons have lost their ability to evacuate the bowels (defecate) under deliberate control. In these patients, the volume of fluid irrigated into the rectum or colon via the anus has the effect of stimulating intestinal peristalsis, with the objective of emptying the large intestine as completely as possible. The result, for the patient, is a stool-free interval during which there is no possibility of the uncontrolled passage of stool through the anus, despite manifest insufficiency of the anal sphincter. Crucial to adequate irrigation is that the injected volume must both mobilize stool in the colon and trigger peristalsis or the defecation reflex. The instillation of the enema solution is usually followed by an interval of several minutes during which the large intestine remains quiet, until peristaltic contractions finally set in and the colon or rectum begins to expel the contents of the bowel. To ensure that the necessary enema volume is retained in the bowel until reflexive expulsion begins, transanally introduced irrigation apparatuses are often equipped with a sealing element. This is usually in the form of a tightly filled balloon that is placed in the terminal rectum; the balloon is mounted on a tube-like inserting element and is designed to keep irrigation fluid from exiting the anus during the waiting period before colonic peristalsis begins.
Currently available stool drainage and irrigation systems are problematic in a number of ways:
When the drainage system is left in place for relatively long dwell times of up to several weeks, there is some of risk pressure-induced injury in the region of the terminal rectum (ulcers) and lesions in the region of the anus (fissures). Pressure ulcers are usually the result of tightly filled balloon bodies that anchor the particular device in the rectum, and that remain in continuous contact with the rectal structures and restrict blood flow. The known systems comprise balloons that are only partially preshaped in the unfilled state, and are inflated to their working size by being subjected to about 100 mbar of pressure so that they can ensure their anchoring function. Anal fissures, on the other hand, result in most cases from the constant friction caused in the anus by the more or less rigid transanal drainage portion of the device, which tends to collapse and lie in folds.
Moreover, the known systems do not offer truly adequate sealing performance, especially in the presence of thin stool or a relatively high-volume flow of irrigation fluid into the colon, thus leading to ongoing fecal incontinence and necessitating meticulous cleaning of the anal folds.
Prior systems tend to slip out of the patient's rectum if pull is exerted on the catheter. This so-called “drop-out” is due in part to the expansion and deformation properties of the materials currently in use, silicone being chief among them. The high compliance of silicone does not allow the balloon to possess adequate dimensional stability, and, when an axial pull is exerted on the drainage system, leads to increasing teardrop-shaped deformation and taper of the balloon anchor, until the latter is so deformed that it prolapses out through the introducing opening that was supposed to be sealed.
Furthermore, conventional elastically expanding anchor balloons do not have a large enough balloon diameter to cover the rectal floor as they lie on it, and thus to achieve the best possible anchoring effect against the anal opening or against axial pull.
To permit long-term catheterization of the particularly sensitive transanal segment with as little trauma as possible, in conventional systems the corresponding segment of the drainage system must be made extremely thin-walled in order for its consistency to be as soft and tissue-friendly as possible. Such a thin-walled implementation of the transanal segment is usually accompanied by a tendency toward torsion or twisting along the longitudinal axis of the transanal segment, thus critically impairing or preventing fecal evacuation.
Moreover, silicones are not odor-tight, and after being in place for a few days usually release a foul fecal odor into the patient's environment. Silicone surfaces are also frequently uneven, and thus, due to the crater-like surface, lead to contamination that is largely resistant to cleaning.
Heretofore available systems made of silicone also are of relatively complex construction, and are adhesive-bonded together from a large number of components in a cost-intensive manual operation.
Newer irrigation equipment, such as, for example, the Peristeen Anal Irrigation System, made by Coloplast, Denmark, is designed for the specific use requirements of patients who are able to self-irrigate or to manage and monitor fecal evacuation on their own. The currently available systems are fairly easy to manipulate, but they do not address requirements that are essential for the user in practical application.
Moreover, the available irrigation systems for achieving continent phases are designed essentially for the self-care patient. Their use in bedridden, insufficiently cooperative, incontinent patients is largely an impossibility.
The main deficiency is usually the sealing properties with respect to the anus, a problem which in most cases is attributable to insufficiently symmetric expansion of the rectally sealing balloon element. This unreliable geometric expansion is caused by the use of high-volume-expandable balloon materials, such as, for example, latex, silicone or varieties of synthetic rubber, which are mounted as a tubular, non-preformed element on the insertion shaft and expand to a spherical shape when filled under pressure. Belly-like bulges which the balloon envelope acquires during this process, so-called herniations, can be so pronounced that the shaft element becomes displaced into the hernia and is no longer at the center of the balloon. With the shaft and the balloon in such a configuration it is impossible for the balloon to rest centrally over the anus on the rectal floor, thus resulting in leakage which the patient often is able to alleviate only by continuously manually correcting the position of the catheter shaft in the anus or that of the balloon in the rectum.
Another problem for patients can be the convenient self-administration of an enema. Available systems, such as, for example, the Persisteen Anal Irrigation System, made by Coloplast, Denmark, function for example on the basis of pneumatic delivery of irrigation solution, which can be controlled via a hand pump. Electric pump systems are also used by self-care patients. The usual choice for continuous drainage, however, is a gravity-fed enema system. But there are no systems on the market that meet the manipulation requirements of all irrigation and drainage modalities.
In current systems, the enema catheter is usually removed from the anus by the patient once peristaltic expulsion of the intestinal contents begins. The expelled contents then evacuate more or less abruptly, and can soil the patient or his or her surroundings. However, conventional enema systems, in which the solution is first administered into the colon via a bag and the expelled intestinal contents are then routed back to the same bag, are frequently unable to accommodate the peristaltically moved volume, and leakage, which may include spurting, can occur at the anal inlet element.
WO 2006/010556 A1 describes a device of the above species for occluding a natural or artificial anus, the device comprising an inflatable balloon with an approximately toroidal structure, formed from a flat, everted tube section, the two ends of which extend approximately coaxially one inside the other and are (each) joined to a cuff, wherein the outer layer of the everted tube section is provided with a radially enlarged, patient-proximal region for insertion into the rectum (intrarectal region) and has a patient-distal region that is tapered relative thereto and that remains at least regionally outside the rectum (transanal region) during use. The transanal portion is constructed of two concentric layers of film, and the concentric tubular films may be lastingly structurally joined to each other by spot connections. However, the compartment thus defined between the layers communicates freely with the lumen of the intrarectal anchor balloon. Both spaces are filled via a single supply line. This has the consequence that due to constant pressure equalization between the two regions, the volume of one region cannot be influenced specifically, which can, for example, detract from the anchoring effect of the intrarectal region.